Improvement in pump-pistons



J.D.ALVORD. PUMP PISTON.

No. 109,994. Patented Dec. 13, 1870.

not fiche fitted can JGSEPH D. ALVORD, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO JAMES WILSON, OF SAME PLACE.

Letters Patent No. 109,994, dated December 13, 1870.

IMPROVEMENT IN PUMP-PISTONS.

The Schedule referred to in these Letters Patent and making out of the same.

T 0 all whom it may concern:

Be it known that I, JOSEPH I). Anvonn, of Bridgeport, iu the county of Fail-field and State of Qonnecticut, have invented a new and useful Improvement in Pistons for Double-actingPumps; and l lo hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawing forming part of this specification, and in which I 2 Figure 1 represents an upper or front face view of a piston constructed in accordance with my invention;

Figure 2, a bottom or opposite face view of the same;

' Figure 3, a longitudinal section, taken indicated by the line a: x in fig. 1; and

Figure 4, a transverse section, taken as denoted by the line yy in fig. 3-

' Similar letters of reference indicate corresponding parts.

My invention has reference to hollow pistons for double-acting pumps, and in which the fluid is discharged through the rod of the piston by the action of valves contained within the piston.

In this class of pumps, when the same are arranged to occupy a vertical position, a ditiiculty has arisen by reason of the valves in the piston only closing, by their weight, against certain of their ports, and 'being dependent upon the pressure of the fluid to'close them against the other ports, so' that in a. slow-working of the pump 'it is possible for no pumping action to take place during the one 's troke, or

My invention obviates this difiiculty, and consists in a novel construction of the hollow piston and ar rangement of its ports and passages, whereby, among other advantages,.all of the piston ports are closedby the weight of its valves, except when forced from their respective seats during the upward or downward stroke.

This insures a prompt closing action of the valves, irrspectively of the pressure of the fluid, so that in a slow working of the pump there is no lost motion or effect.

The same construction and arrangementof the piston and its ports or passages is applicable to pumps arranged to work in a horizontal posit-ion, but it will sn'flice here to generally describe the invention as appliedto a pump occupying a vertical position.

Referring to the accompanying drawing- 13. represents the piston of a double-acting pump, an

' R, its hollow rod; which communicates with the interior of the piston between side passages to a. that serve to contain the valves B B.

These valves, which control ports l) b, are alternately opened and closed during. the reciprocating action of the pump, the valve B closing in the downstroke, and the valve B in the lip-stroke of the piston, but both closing by their gravity, irrespective of the pressure of the fluid, by reason of the arrangemeat of the ports b b, on the under sides or faces of the valves, and the arrangement of the passages or openings, and a chamber within the piston, as hereinaiter described.

Opening from the upper or front face of the piston are one or more passages, 0, arranged to extend longitudiually within the piston-heai'l, and terminating in a chamber, D, on the iower or opposite face of the piston, and with which the port b is made to commuuicate.

The other port b is in direct communication with the space below the piston;

In the down-stroke of the pump the valve B is lifted, and' fluid passes direct from below the piston to and up the hollow rod R, the valve B closing, by

its gravity, and suction taking place on the upper side of the piston.

In the reverse action or lip-stroke of the pump the valve B closes by its gravity, and the valve B is lifted,

readily effect-s tliealternate lift-in g of the valves, which, .how'ever,.do notnecessarily depend upon the pressure of the fluid to close them; but so soon as the fluid is diverted from lifting either valve, by reversal in the. stroke of the piston or otherwise, either valve B B closes by its own gravity; thus a prompt action is socured for the valves independently of pressure, and aperfect working of the pump insured at or under all velocities.

\Vhen the pump is arranged to work' in a horizontal position, then the upperface of the piston may he denominated its front, and the lower face of the piston its back. I

What is here claimed, and desired to be secured by Letters Patent-, is-- A doable-acting pump-piston, provided with valves B B and passages G, D, and D, so arranged that the said valves are caused to open alternately in the same direction regardless of the direction in which the piston may be traveling,substantially as specified.

Witnesses: J. I). ALVORD.

A. R.,LAcnY, i F. Hum). 

